1. Field of the Invention
The present invention relates to a navigation apparatus for executing navigation at the time of selecting a service provider and, more particularly, to a navigation apparatus for displaying, on a user terminal, a service selection menu from which a user can select a service provider which provides multimedia service.
2. Description of the Related Art
There are network systems for connecting a user terminal to the service provider selected by the user from among a plurality of service providers which provide various kinds of multimedia service such as a video on demand (VOD) and on-line shopping, and providing the multimedia service from the selected service provider by utilizing a broadband-ISDN.
In such a network system, a navigation function is essential so that a user terminal can efficiently utilize the multimedia service provided by the service provider. A conventional navigation server, however, only serves to connect a user terminal to the service provider which provides the service designated by the user terminal.
For this reason, the user cannot judge whether or not the designated service is applicable to the user terminal until it is connected to the service provider. As a result, the connection is sometimes cut due to a shortage of network resource (e.g., shortage of band) or disagreement about how to decode a data stream. Even if a path is safely set between the user terminal and the service provider, it sometimes happens that since it is impossible to secure a sufficient transmission band, the service is not practically usable, or that the line is inconveniently held for a long time due to the transfer of an unexpectedly large amount of data. Another problem is that excessive access to a popular service provider makes it difficult to access smoothly.
Therefore, there is a strong demand for a network system which utilizes a broadband-ISDN and has a more useful service provider supporting function. If a network controller provided with a function of connecting a user terminal to a service provider and a function of controlling the traffic of the line is linked with a navigation server for executing navigation at the time of selecting a service provider, such a network system will be realized. In addition, in a broadband-ISDN in which the communication quality is different depending upon the network resource (band) allocated to the offer of service, simple navigation of a service provider is insufficient. There is, therefore, a demand for a more valuable function of navigating a user terminal to a service provider in due consideration of the type of user terminal and service provider, and the network resource (band) necessary for the allocation of the offer of the service.